Continuity mistake: When Jamie backs up into Michael in the drug store his hands are at his sides.Yet when she looks up at him he's putting on his mask.
Plot hole: Toward the end, when Jamie and Rachel are being taken to safety by the vigilantes, Michael suddenly climbs over the back of the truck and slays all the guys one by one. There is no way he could have been 'hiding' under the truck as he was still deep inside the school when the truck sped out of the lot and down the road. Obviously added for dramatic effect at the end.
Visible crew/equipment: When the sheriff and the officer are talking after getting the gun from his car, you can see a crew member in the background (doorway).
Continuity mistake: When the sheriff's daughter is killed she goes from wearing a T-shirt to a flannel shirt.
Suggested correction: She changed her clothes because Rachel poured coffee on her T-shirt in a previous scene.
Continuity mistake: When Michael throws Dr. Loomis out the window at the school, the next shot shows him being thrown through a glass door.
